Catalytic composition for dimerizing, co-dimerizing and oligomerizing olefins

ABSTRACT

A catalytic composition comprising at least one nickel compound mixed or complexed with at least one tertiary phosphine or a phosphite carrying a functional group, at least partly dissolved in a non-aqueous medium with an ionic nature resulting from bringing at least one aluminum halide into contact with at least one quaternary ammonium halide and/or at least one quaternary phosphonium halide is useful for dimerizing, co-dimerizing and oligomerizing olefins. Functional group include, but are not limited to, an amine, a cyclic amine, a nitrogen-containing heterocycle, an ester, an acid, an alcohol, a quaternary ammonium, a quaternary phosphonium, a sulfonium, a sulfonate or a phosphonate group.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a catalytic composition used fordimerizing, co-dimerizing and oligomerizing olefins. More particularly,it relates to a composition resulting from at least partly dissolving atleast one nickel compound mixed or complexed with a tertiary phosphineor a phoshite carrying a functional group, in a liquid mixture of ionicnature of at least one quaternary ammonium halide and/or at least onequaternary phosphonium halide, at least one aluminum halide andoptionally at least one organometallic aluminum compound.

[0003] 2. Description of the Prior Art

[0004] French Patent No. 2,611,700 describes the use of liquids of ionicnature formed from aluminum halides and quaternary ammonium halides assolvents for organometallic nickel complexes to catalyze olefindimerization. The use of such media, which are not miscible withaliphatic hydrocarbons, in particular with the products from olefindimerization, enables homogeneous catalysts to be used more effectively.French Patent No. 2,659,871 describes a liquid composition with an ionicnature resulting from bringing quaternary ammonium halides and/orquaternary phosphonium halides into contact with alkylaluminum dihalidesand optionally also an aluminum trihalide. That same patent describesthe use of such media as solvents for transition metal complexes, inparticular nickel complexes containing no nickel-carbon bond, which aretransformed into catalysts for olefin oligomerization. In the presenttext, such media will henceforth be termed “molten salts”, as they areliquid at moderate temperatures.

[0005] During those studies, it was shown that the most active and moststable nickel catalysts are obtained in “molten salts” constituted byone molar equivalent of an ammonium halide and/or a phosphonium halidewith one equivalent and more of an aluminum trihalide, and optionallyany quantity of an alkyl aluminum dihalide. That formulation has beenshown to be particularly interesting as nickel complexes dissolved in ithave high catalytic activity.

[0006] It has been shown that under such conditions and when thereaction is carried out in a semi-open system with a continuous olefinsupply and continuous separation of the products after decanting, asmall but non-negligible proportion of the nickel is extracted in theorganic phase.

[0007] Further, it has been shown that under the conditions described inFrench Patent No. 2,611,700, the “phosphine effect”, as described by G.Wilke et al., in Ind. Eng. Chem., 1970, 62, No. 12, p. 34, and in U. K.Patent No. 1,058,680, which reports the influence of substituentscarried by the phosphorus atom on the mode of enchainment of propylenemolecules during catalytic dimerization by nickel, rapidly disappearsover time. That unexplained phenomenon has deleterious consequencessince it does not produce the desired selectivities.

[0008] Further, French Patent No. 2,710,280 shows that adding anaromatic hydrocarbon to a “molten salt” can overcome this problem andresult in catalysts with high activity which are more stable and whichhave a high selectivity for the most highly branched isomers. However,the aromatic hydrocarbon is continuously extracted in the organic phaseconstituted by the products, which implies that it must be separated andrecycled to the reactor.

SUMMARY OF THE INVENTION

[0009] It has now been discovered that the use of a tertiary phosphinecarrying a functional group or a phosphite carrying a functional groupor a nickel complex formed with a tertiary phosphine or a functionalizedphosphite that is soluble in the “molten salt” results in catalysts withhigh activity which are stable over time and wherein the extraction ofnickel from the reaction products is reduced to a minimum. This has theresult of reducing the consumption of the catalyst and thus of improvingthe economics of the process.

DETAILED DESCRIPTION OF THE INVENTION

[0010] The invention provides a catalytic composition comprising atleast one nickel compound mixed or complexed with at least one tertiaryphosphine or a phosphite carrying a functional group, at least partlydissolved in a non aqueous medium with an ionic nature (“molten salt”type medium), resulting from bringing at least one aluminum halide(product B) into contact with at least one quaternary ammonium halideand/or at least one quaternary phosphonium halide (product A), the“molten salt” type medium possibly further comprising at least oneorganometallic aluminum compound (product C).

[0011] Thus the “molten salt” type medium, in which the nickel compoundmixed or complexed with at least one tertiary phosphine carrying afunctional group or at least one phosphite carrying a function group isdissolved, is constituted by mixing:

[0012] a) at least one quaternary ammonium and/or quaternary phosphoniumhalide, more particularly a chloride and/or bromide (product A);

[0013] b) at least one aluminum halide (product B); and

[0014] c) optionally, at least one organometallic aluminum compound(product C).

[0015] Preferred quaternary ammonium and/or phosphonium halides that canbe used within the context of the invention (product A), are:

[0016] hose with general formula NR¹R²R³R⁴X (with the exception ofNH₄X), PR¹R²R³R⁴X, R¹R²N=CR³R⁴X or R¹R²P=CR³R⁴X, where X represents Clor Br and R¹, R², R³ and R⁴, which may be identical or different, eachrepresent hydrogen or a hydrocarbyl residue containing 1 to 12 carbonatoms, for example saturated or unsaturated alkyl, cycloalkyl oraromatic groups, aryl groups or aralkyl groups, containing 1 to 12carbon atoms, it being understood that preferably, only one ofsubstituents R¹, R², R³ and R⁴ represents hydrogen;

[0017] or one of the following general formulae:

[0018] where the nitrogen-containing or phosphorus-containingheterocycles containing 1, 2 or 3 nitrogen and/or phosphorus atoms areconstituted by 4 to 10 atoms and X, R¹ and R² are defined as above.

[0019] Examples which can be cited are tetrabutyl phosphonium chloride,N-butyl pyridinium chloride, ethylpyridinium bromide, 3-butyl-1-methylimidazolium chloride, diethylpyrazolium chloride, pyridiniumhydrochloride, trimethylphenyl ammonium chloride and 3-ethyl-1-methylimidazolium chloride. These salts can be used alone or as a mixture.

[0020] The aluminum halides used as products B of the invention areessentially aluminum chloride and bromide.

[0021] The organometallic aluminum compounds used as optional products Cof the invention have general formula AlR_(x)X_(3−x) in which R is alinear or branched alkyl residue containing 2 to 8 carbon atoms, X ischlorine or bromine and the value of x is 1, 2 or 3. Examples oforganometallic aluminum compounds that can be used are isobutylaluminumsesquichloride, ethylaluminum sesquichloride, dichloroisobutyl aluminum,dichloroethyl aluminum and chlorodiethylaluminum.

[0022] The components of the “molten salts” as defined above aregenerally used in A:B mole ratios of 1:0.5 to 1:3, preferably 1:1 to1:2; product C is used in a mole ratio of at most 100:1 with product B,preferably 0.005:1 to 10:1. However, the components and theirproportions must be such that the mixture is liquid at the temperatureat which the nickel compound and the functionalized tertiary phosphineor functionalized phosphite are introduced, although the catalyticdimerization reaction

[0023] Examples of nickel compounds used in the catalytic compositionsof the invention are the chloride, bromide, sulfate, carboxylates (forexample the 2-ethylhexanoate), phenates and acetyl acetonate. It is alsopossible to use organometallic nickel complexes which may or may notcontain phosphines or phosphites. These nickel complexes are used as amixture with a functionalized tertiary phosphine or a functionalizedphosphite. It is also possible to use nickel complexes that are alreadycomplexed with a tertiary phosphine carrying a function or a phosphitecarrying a function.

[0024] The functional phosphines used as a mixture with (or to complex)the nickel compounds of the invention have general formulae PR′₁R′₂R′₃and R′₁R′₂P-R′-PR′₁R′₂, where R′₁, R′₂ and R′₃, which may be identicalor different, are alkyl, cycloalkyl, aryl or aralkyl radicals containing1 to 10 carbon atoms at least one of which carries a functional groupsuch as an amine, a cyclic amine, a nitrogen-containing heterocycle, anester, an acid, an alcohol, a quaternary ammonium, a quaternaryphosphonium, a sulfonium, a sulfonate or a phosphonate and R′ is adivalent aliphatic residue containing 1 to 6 carbon atoms.

[0025] The functional phosphines can be selected from compoundscontaining pyridine or imidazole substituents or their quaternizedderivatives containing pyridinium or imidazolium substituents thatsatisfy formulae 1 to 7 defined below.

[0026] Examples of functional phosphines carrying a pyridine substituentare 2-dicyclo-pentylphosphinoethyl-4-pyridine with formula (1),2-dicyclopentylphosphinoethyl-2-pyridine with formula (2),2-diisobutylphosphinoethyl-4-pyridine with formula (1b),2-diisopropylphosphinoethyl-4-pyridine with formula (4) and theirquaternization derivatives with formula (3), where R is an alkyl groupcontaining 1 to 10 carbon atoms and X is a weakly co-ordinating anion.Examples of weakly coordinating anions which can be cited aretetrafluoroborate, hexafluorophoshate, tetrachloroaluminate,hexafluoroantimonate, carboxylate anions such as acetate,trifluoroacetate, trifluorosulfonate, and the anions N(CF₃SO₂)₂ ⁻ andC(CF₃SO₂)₃ ⁻. Examples of quaternization derivatives are2-dicyclopentylphosphinoethyl-N-ethyl pyridinium tetrafluoroborate withformula (3a), or 2-dicyclopentylphosphinoethyl-N-ethyl pyridiniumchloride with formula (3b).

[0027] Examples of functional phosphines carrying an imidazolesubstituent which can be cited are2-dicyclopentylphosphinoethyl-N-imidazole with formula (5),2-diisopropylphosphinoethyl-N-imidazole with formula (7),2-diisobutylphosphinoethyl-N-imidazole with formula (7b) and theirquaternization derivatives with formula (6), where R is an alkyl groupcontaining 1 to 10 carbon atoms and X is a weakly coordinating anion (asdefined above), such as 2-dicyclopentylphosphinoethyl-1-methylimidazolium tetrafluoroborate with formula (6a).

[0028] The functionalized phosphites used as a mixture with (or tocomplex the nickel compounds of the invention) have general formulaeP(OR″₁) (OR″₂) (OR″₃) and (—O—R″₅—O—)P(OR″₂), where R″₁, R″₂, R″₃ andR″₅, which may be identical or different, are aryl or aralkyl radicalsat least one of which carries a functional group such as an amine, acyclic amine, a nitrogen-containing heterocycle, an ester, an acid, analcohol, a quaternary ammonium, a quaternary phosphonium, a sulfonium, asulfonate or a phosphonate.

[0029] The functional phosphites can be selected from compounds withformulae 9 to 11 described below.

[0030] It is possible to use phosphites represented by general formula(9) (where x is 0 to 2), where Y⁺ can be an organic cation such as aquaternary ammonium or quaternary phosphonium with general formulaNR¹R²R³R⁴ and PR¹R²R³R⁴ where R¹, R², R³ and R⁴, which may be identicalor different, each represent hydrogen, an aliphatic (saturated orunsaturated) or aromatic hydrocarbon group containing 1 to 12 carbonatoms; the quaternary ammonium and/or phosphonium ions can also bederivatives of heterocycles containing 1, 2 or 3 nitrogen and/orphosphorus atoms or an alkaline cation such as Li⁺, Na⁺ or K⁺ [formula(9b)].

[0031] It is also possible to use phosphites represented by generalformula (10), where cation Y⁺ can be an alkali cation such as Li⁺, Na⁺or K⁺ [formula (10b)] or an organic cation such as a quaternary ammoniumor quaternary phosphonium with general formula NR¹R²R³R⁴ and PR¹R²R³R⁴where R¹, R², R³ and R⁴, which may be identical or different, eachrepresent hydrogen, an aliphatic (saturated or unsaturated) or aromatichydrocarbon group containing 1 to 12 carbon atoms, the quaternaryammonium and/or phosphonium ions can also be derivatives of heterocyclescontaining 1, 2 or 3 nitrogen and/or phosphorus atoms.

[0032] As examples of quaternary ammonium or phosphonium cations thatcan be found in formulae (9) and (10), can be cited tetrabutylammonium,as in formula (9a) or formula (10a), tetrabutylphosphonium,N-butylpyridinium, ethylpyridinium, 3-butyl-1-methylimidazolium,diethyl-pyrazolium and trimethylphenylammonium.

[0033] Finally, it is possible to use phosphites represented by generalformula (11), where anion X is a weakly coordinating anion. Examples ofweakly coordinating anions which can be cited are tetrafluoroborate orhexafluorophosphate, as in formula (11a), tetrachloroaluminate,hexafluoro-antimonate, carboxylate anions such as acetate ortrifluoroacetate, trifluorosultonate, the N(CF₃SO₂)₂ ⁻ and C(CF₃SO₂)₃ ⁻and the tetraphenylborate anion and tetraphenylborate anions where thearomatic rings are substituted.

[0034] As examples of nickel compounds that can be used to constitutethe catalytic compositions of the invention, can be cited the complexes[NiCl₂, 1.5 P(2-dicyclopentylethyl-4-pyridine)]₂, [NiCl₂,2P(2-dicyclopentylethyl-N-ethyl pyridinium tetrafluoroborate)], [Ni₂Cl₄,(2-dicyclopentylphosphinoethyl-N-ethyl pyridinium tetrafluoroborate)₃,1.5 CH₂Cl₂], NiCl₂, 2 pyridine mixed with at least one equivalent offunctionalized tertiary phosphine or functionalized phosphite, nickelchloride mixed with at least one equivalent of2-dicyclopentylphosphinoethyl-4-pyridine, nickel acetate mixed with atleast one equivalent of 2-dicyclopentylphosphinoethyl-4-pyridine, nickel(2-ethyl hexanoate) octoate mixed with at least one equivalent of2-dicyclopentylphosphinoethyl-4-pyridine and2-dicyclopentylphosphinoethyl-4-pyridine π-allyl nickel chloride.

[0035] The compounds forming part of the catalytic composition of theinvention can be mixed in any order. The mixture can be produced bysimply bringing them into contact followed by agitation until ahomogeneous liquid is formed. This mixture can be produced outside thedimerization or oligomerization reactor or, as is preferable, in thereactor.

[0036] More particular olefins that can be dimerized, co-dimerized oroligomerized using the catalytic compositions of the invention areethylene, propylene, n-butenes and n-pentenes, used alone or as amixture (co-dimerization), pure or diluted in an alkane, such as thosefound in cuts from oil refining processes, such as catalytic cracking orsteam cracking.

[0037] The catalytic olefin dimerization or oligomerization reaction canbe carried out in a closed system, in a semi-open system orcontinuously, with one or more reaction stages. Vigorous agitation mustbe carried out to ensure good contact between the reactant or reactantsand the catalytic mixture. The reaction temperature can be from −40° C.to +70° C., preferably −20° C. to +50° C. It is possible to operateabove or below the fusion temperature of the medium, the dispersed solidstate not being a limitation to the proper conduct of the reaction. Theheat engendered in the reaction can be eliminated using any means knownto the skilled person. The pressure can be from atmospheric pressure to20 MPa, preferably atmospheric pressure to 5 MPa. The reaction productsand the reactant or reactants that has/have not reacted are separatedfrom the catalytic system simply by decanting, then fractionation.

[0038] The entire disclosure of all applications, patents andpublications, cited above and below, and of corresponding Frenchapplication 00/01512, filed Dec. 4, 2000, are hereby incorporated byreference.

[0039] The following examples illustrate the invention without limitingits scope.

EXAMPLE 1

[0040] Preparation of Ionic Solvent

[0041] 17.5 g (0.1 mole) of 1-butyl-3-methyl imidazolium chloride, 16.3g (0.122 mole) of sublimed aluminum chloride, 1.6 g (0.0126 mole) ofdichloroethyl aluminum was mixed at ambient temperature. A liquid wasobtained.

EXAMPLE 2

[0042] Preparation of the Complex [NiCl₂, 1.5P(2-dicyclopentylethyl-4-pyridine)]₂

[0043] 2.37 g of NiCl₂, 6H₂O and 10 ml of absolute methanol wereintroduced into a Schlenk tube maintained under an argon atmosphere.After the nickel salt had dissolved, 20 ml of pentane was added. The 2phases were agitated and 5.33 g of tertiary phosphine with formula (1)(20 mmoles) was added. After 2 hours agitation, the red precipitate wasfiltered. 5.82 g was obtained. Elemental analysis corresponded to thecomplex with formula [NiCl₂, 1.5 P(2-dicyclopentylethyl-4-pyridine)]₂(M=1085 g; 10.7% by weight of Ni).

EXAMPLE 3

[0044] Quaternization of Pyridine in the Complex Described in Example 2

[0045]3.72 g of the complex described in Example 2 was placed in aSchlenk tube and dichloromethane was added. Then a solution oftetrafluoroborate oxonium in dichloromethane (2.14 g of Et₃O⁺BF₄ ⁻) wasadded dropwise. It was agitated for 4 hours, at the end of which perioda red solution was obtained. The solvent was evaporated off and 20 ml ofether was added. The red crystalline solid obtained was filtered off.4.56 g was obtained. Elemental analysis corresponded to the complex withformula: Ni₂Cl₄(P-N⁺EtBF₄ ⁻)₃, 1.5 CH₂Cl₂, where P-N is the ligand withformula (1).

EXAMPLE 4

[0046] Propylene Dimerization

[0047] A glass reactor provided with a temperature sensor, a magneticbar in the lower stage (20 ml volume) to ensure proper agitation and adouble envelope for circulating a cooling liquid was purged of air andmoisture and maintained at an atmospheric pressure of 99% purepropylene. 0.03 mmole of the complex prepared in Example 2 (0.06 mmoleof Ni) was introduced then the temperature was reduced to 10° C. and 5ml of the liquid composition prepared above (Example 1) was injectedusing a syringe, along with 7 ml of heptane. Agitation was commenced andimmediately, propylene absorption was observed. When the non-agitatedupper stage was full of liquid, the major portion of the hydrocarbonphase had been extracted. The reaction was stopped after 7 hours (5extractions). At that time, 175 kg of products per gram of Ni had beenproduced. Analysis of the different fractions showed that they werecomposed of 77% of dimers. The composition of the dimers, which waspractically identical in all of the fractions, was 67% of2,3-dimethylbutenes, and 29% of methyl pentenes, the remainder beingn-hexenes.

EXAMPLE 5

[0048] Propylene Dimerization

[0049] The procedure of Example 4 was carried out, with the exceptionthat the molten salt prepared for this purpose was used, and that 0.05mmole of nickel (2-ethylhexanoate) octoate and 0.5 mmole of2-dicyclopentylphosphinoethyl-4-pyridine were introduced. The reactionperiod was 7 hours 15 minutes, at the end of which 5 fractions had beenextracted and 220 kg of products per gram of Ni had been produced. Thedimer selectivity was 78%. The selectivity for 2,3-dimethylbutenes was66% in the first fraction and 63% in the final fraction.

EXAMPLE 6

[0050] Propylene Dimerization

[0051] The procedure of Example 4 was followed, with the exception thatthe molten salt for this purpose was used, and that 45 mg of the complexprepared in Example 3 was introduced. The reaction period was 7 hours 15minutes, at the end of which 5 fractions had been extracted and 117 kgof products per gram of Ni had been produced. The dimer selectivity was74-79%. The selectivity for 2,3-dimethylbutenes was 65% and was constantfor the various fractions.

EXAMPLE 7 (Comparative)

[0052] Propylene Dimerization

[0053] The procedure of Example 4 was followed, with the exception thatthe molten salt used was that prepared in Example 1, introducing 0.05mmole of the complex NiCl₂, 2P(cyclohexyl)₃. The reaction was left for 8hours 30 minutes, at the end of which 10 fractions had been extracted.137 kg of products per gram of Ni were produced, with a dimerselectivity of 83%. The selectivity for 2,3-dimethylbutenes was 70% inthe first fraction; it dropped to 35% in the third and to 10% in thesixth fraction. It was 6% in the tenth fraction.

EXAMPLE 8

[0054] Butene Dimerization

[0055] The molten salt prepared in Example 1 was used. The procedure ofExample 4 was used with the exception that butene-1 was used instead ofpropylene. 0.115 mmole (0.23 mmoles of Ni=13.5 mg of Ni) of the complexprepared in Example 2 was introduced into the lower stage of the glassreactor then the temperature was reduced to 10° C. and 5 ml of the saltand 20 ml of heptane were injected under a butene atmosphere. Agitationwas commenced and butene absorption was observed. When the non-agitatedupper stage was full of fluid, the major portion of the hydrocarbonphase had been extracted. The reaction was stopped after 21 hours (28extractions). At that moment, 1708 g of butene had been consumed. 76 kgof products per gram of Ni had been produced. Analysis of the differentfractions showed that they were composed of 80% of dimers. The ensembleof the organic fractions was treated with 10% nitric acid. 2.25 ml of Niwas found in the nitric acid (X-ray fluorescence determination). Aproportion of 19% by weight of nickel (calculated with respect to thenickel introduced) had thus been extracted with the products after 21hours of reaction.

EXAMPLE 9

[0056] Preparation of Ligand with Formula (9a)

[0057] 26.1 g (65.58 mmole) of tetrabutylammonium 4-hydroxy benzenesulfonate and 100 ml of toluene were introduced into a three-neckedflask. It was heated to 140° C. and over 1 hour, 6.82 g (21.8 mmole) oftriphenylphosphite and 0.385 g of trioctylamine were added. It was leftfor another 1 hour at 140° C. then placed under vacuum (10⁻⁶ mm Hg) for6 hours at 110° C. The product obtained was analyzed by ³¹P NMR. It wasconstituted by a mixture of 3 phosphites corresponding to x=0, 1 and 2.

EXAMPLE 10

[0058] Butene Dimerization

[0059] The molten salt prepared in Example 1 was used. The procedure ofExample 8 was followed, with the exception that the complex NiCl₂,2-pyridine (0.2 mmole; 11.8 mg Ni) was used as the catalyst precursor towhich 5 equivalents (670 mg) with respect to the nickel of the phosphitewith formula (9a) had been added, prepared as described in Example 9.The reaction was stopped after 43.5 hours (22 extractions). At thattime, 1428 g of butene had been consumed. 73 kg of products per gram ofNi was produced. Analysis of the different fractions showed that theywere composed of 97-99% of dimers. The ensemble of the organic fractionswas treated with 10% nitric acid. 1 mg of Ni was found in the nitricacid (X-ray fluorescence determination). A proportion of 8.5% by weightof nickel (calculated with respect to the nickel introduced) had thusbeen extracted with the products after 43.5 hours of reaction.

EXAMPLE 11

[0060] Butene Dimerization

[0061] The procedure of Example 10 was followed, with the exception that1 equivalent (134 mg) of the phosphite with formula (9a) was added withrespect to the complex NiCl₂, 2-pyridine. The reaction was stopped after35 hours (12 extractions). At that time, 2102 g of butene had beenconsumed. 107 kg of products per gram of Ni was produced. Analysis ofthe different fractions showed that they were composed of 95-97% ofdimers. The ensemble of the organic fractions was treated with 10%nitric acid. 1.4 mg of Ni was found in the nitric acid (X-rayfluorescence determination). A proportion of 12% by weight of nickel(calculated with respect to the nickel introduced) had thus beenextracted with the products after 35 hours of reaction.

EXAMPLE 12 (Comparative)

[0062] Butene Dimerization

[0063] The molten salt prepared in Example 1 was used. The procedure ofExample 7 was followed, with the exception that the complex NiCl₂,2P(cyclohexyl)₃ (0.2 mmole of Ni; 11.8 mg Ni) was used as the catalystprecursor, and 40 ml of heptane. The reaction was stopped after 14.8hours (9 extractions). A substantial reduction in butene consumption wasobserved. At that time, 815 g of butene had been consumed. 84 kg ofproducts per gram of Ni was produced. Analysis of the differentfractions showed that they were composed of 90-94% of dimers. Theensemble of the organic fractions was treated with 10% nitric acid. 6.2mg of Ni was found in the nitric acid (X-ray fluorescencedetermination). A proportion of 52% by weight of nickel (calculated withrespect to the nickel introduced) had thus been extracted with theproducts after 14.8 hours of reaction.

[0064] The preceding examples can be repeated with similar success bysubstituting the generically or specifically described reactants and/oroperating conditions of this invention for those used in the precedingexamples.

[0065] From the foregoing description, one skilled in the art can easilyascertain the essential characteristics of this invention and, withoutdeparting from the spirit and scope thereof, can make various changesand modifications of the invention to adapt it to various usages andconditions.

1. A catalytic composition characterized in that it comprises at leastone nickel compound mixed or complexed with at least one tertiaryphosphine or a phosphite carrying a functional group, at least partlydissolved in a non aqueous medium with an ionic nature resulting frombringing at least one aluminum halide (product B) into contact with atleast one quaternary ammonium halide and/or at least one quaternaryphosphonium halide (product A)
 2. A catalytic composition according toclaim 1 characterized in that the nickel compound is selected from thechloride, bromide, sulfate, carboxylates, phenates and acetylacetonate.3. A catalytic composition according to claim 1 or claim 2 characterizedin that the tertiary phosphine carrying a functional group has one ofthe general formulae PR′₁R′₂R′₃ or R′₁R′₂P-R′-PR′₁R′₂, where R′₁, R′₂and R′₃, which may be identical or different, are alkyl, cycloalkyl,aryl or aralkyl radicals containing 1 to 10 carbon atoms at least one ofwhich carries a functional group selected from an amine, a cyclic amine,a nitrogen-containing heterocycle, an ester, an acid, an alcohol, aquaternary ammonium, a quaternary phosphonium, a sulfonium, a sulfonateand a phosphonate group and R′ is a divalent aliphatic residuecontaining 1 to 6 carbon atoms.
 4. A catalytic composition according toclaim 3 characterized in that the functional tertiary phosphine isselected from phosphines containing pyridine or imidazole substituentsand their quaternization derivatives with pyridinium or imidazoliumsubstituents.
 5. A catalytic composition according to claim 4characterized in that the functional tertiary phosphine carrying apyridine or imidazole substituent is selected from2-dicyclopentylphosphinoethyl-4-pyridine,2-dicyclopentylphosphinoethyl-2-pyridine,2-diisobutylphosphinoethyl-4-pyridine,2-diisopropylphosphinoethyl-4-pyridine,2-dicyclopentylphosphinoethyl-N-imidazole,2-diisopropylphosphinoethyl-N-imidazole and2-diisobutylphosphinoethyl-N-imidazole.
 6. A catalytic compositionaccording to claim 4 characterized in that the functional tertiaryphosphine carrying a pyridinium or imidazolium substituent is aquaternization derivative with one of formulae (3) or (6) where R is analkyl group containing 1 to 10 carbon atoms and X is a weaklycoordinating anion.
 7. A catalytic composition according to claim 6characterized in that the weakly coordinating anion is selected fromtetrafluoroborate, hexafluorophosphate, tetrachloroaluminate,hexafluoroantimonate, carboxylate anions such as acetate ortrifluoroacetate, trifluorosulfonate, and the N(CF₃SO₂)₂ ⁻ andC(CF₃SO₂)₃ ⁻ anions.
 8. A catalytic composition according to claim 6 orclaim 7 characterized in that the functional tertiary phosphine carryinga pyridinium or imidazolium substituent is selected from2-dicyclopentylphosphinoethyl-N-ethyl pyridinium tetrafluoroborate,2-dicyclopentylphosphinoethyl-N-ethyl pyridinium chloride and2-dicyclopentylphosphinoethyl- 1-methylimidazolium tetrafluoroborate. 9.A catalytic composition according to claim 1 or claim 2 characterized inthat the functional phosphite has one of the general formulae: P(OR″₁)(OR″₂) (OR″₃) or (—O—R″₅—O—)P(OR″₂); where R″₁, R″₂, R″₃ and R″₅, whichmay be identical or different, are aryl or aralkyl radicals wherein atleast one carries a functional group such as an amine, a cyclic amine, anitrogen-containing heterocycle, an ester, an acid, an alcohol, aquaternary ammonium, a quaternary phosphonium, a sulfonium, a sulfonateor a phosphonate.
 10. A catalytic composition according to claim 9characterized in that the functional phosphite has general formula (9)where x=0 to 2, in which cation Y: is selected from sodium, lithium orpotassium and the quaternary ammonium and quaternary phosphonium cationshave general formulae: N⁺R¹R²R³R⁴ and P⁺R¹R²R³R⁴ where R¹, R², R³ andR⁴, which may be identical or different, each represent hydrogen, asaturated or unsaturated aliphatic or an aromatic hydrocarbon groupcontaining 1 to 12 carbon atoms; or is derived from a heterocyclecontaining 1, 2 or 3 nitrogen and/or phosphorus atoms.
 11. A catalyticcomposition according to claim 9 characterized in that the phosphite hasgeneral formula (10) where cation Y is selected from sodium, lithium orpotassium and quaternary ammonium and quaternary phosphonium cationswith general formulae: N⁺R¹R²R³R⁴ and P⁺R¹R²R³R⁴ where R¹, R², R³ andR⁴, which may be identical or different, each represent hydrogen, asaturated or unsaturated aliphatic or an aromatic hydrocarbon groupcontaining 1 to 12 carbon atoms; or a heterocyclic derivative containing1, 2 or 3 nitrogen and/or phosphorus atoms.
 12. A catalytic compositionaccording to claim 10 or claim 11 characterized in that the quaternaryammonium or phosphonium is selected from tetrabutylammonium,tetrabutylphosphonium, N-butylpyridinium, ethylpyridinium,3-butyl-1-methyl imidazolium, diethylpyrazolium and trimethylphenylammonium.
 13. A catalytic composition according to claim 9 characterizedin that the phosphite has general formula (11) where anion X is a weaklycoordinating anion.
 14. A catalytic composition according to claim 13characterized in that the weakly coordinating anion is selected fromtetrafluoroborate, hexafluorophosphate, tetrachloroaluminate,hexafluoroantimonate, carboxylate anions such as acetate,trifluoroacetate, trifluorosulfonate, the N(CF₃SO₂)₂ ⁻ and C(CF₃SO₂)₃ ⁻anions, the tetraphenylborate anion and tetraphenylborate anions whereinthe aromatic rings are substituted.
 15. A catalytic compositionaccording to claims 9 to 14 characterized in that the tertiary phosphitecarrying a functional group is selected from phosphites described byformulae (9a), (9b), (10a), (10b) and (11a).
 16. A catalytic compositionaccording to any one of claims 1 to 15 characterized in that the nickelcompound mixed or complexed with at least one tertiary phosphinecarrying a functional group is selected from the following complexes:[NiCl₂, 1.5P(2-dicyclopentylethyl-4-pyridine)]₂; [NiCl₂,2P(2-dicyclopentylethyl-N-ethyl pyridinium tetrafluoroborate)]₂;[Ni₂Cl₄, (2-dicyclopentylphosphinoethyl-N-ethylpyridiniumtetrafluoroborate)₃, 1.5CH₂Cl₂]; NiCl₂, 2 pyridine mixed with at leastone equivalent of functionalized tertiary phosphine or functionalizedphosphite; nickel chloride mixed with at least one equivalent of2-dicyclopentylphosphinoethyl-4-pyridine; nickel acetate mixed with atleast one equivalent of 2-dicyclopentylphosphinoethyl-4-pyridine; nickel(2-ethyl hexanoate) octoate mixed with at least one equivalent of2-dicyclopentylphosphinoethyl-4-pyridine; and2-dicyclopentylphosphinoethyl-4-pyridine π-allyl nickel chloride.
 17. Acatalytic composition according to any one of claims 1 to 16characterized in that the quaternary ammonium halide or quaternaryphosphonium halide used as product A satisfies: one of general formulae:NR¹R²R³R⁴X with the exception of NH₄X, PR¹R²R³R⁴X, R¹R²N=CR³R⁴X orR¹R²P=CR³R⁴X, where X represents Cl or Br and R¹, R², R³ and R⁴, whichmay be identical or different, each represent hydrogen or a hydrocarbylresidue containing 1 to 12 carbon atoms; or one of the following generalformulae:

where the nitrogen-containing or phosphorus-containing heterocyclescontaining 1, 2 or 3 nitrogen and/or phosphorus atoms are constituted by4 to 10 atoms and X, R¹ and R² are defined as above.
 18. A catalyticcomposition according to claim 17 characterized in that the quaternaryammonium halide or quaternary phosphonium halide is tetrabutylphosphonium chloride, N-butyl pyridinium chloride, ethylpyridiniumbromide, 3-butyl-1-methyl imidazolium chloride, diethylpyrazoliumchloride, pyridinium hydrochloride, trimethylphenylammonium chloride or1-ethyl-3-methyl imidazolium chloride.
 19. A catalytic compositionaccording to any one of claims 1 to 18 characterized in that thealuminum halide used as product B is aluminum chloride or bromide.
 20. Acatalytic composition according to any one of claims 1 to 19characterized in that products A and B are used in an A:B mole ratio of1:0.5 to 1:3.
 21. A catalytic composition according to any one of claims1 to 20 characterized in that the non-aqueous medium with an ionicnature also comprises a product C, consisting of at least oneorganometallic aluminum compound.
 22. A catalytic composition accordingto claim 21 characterized in that the organometallic aluminum compoundused as optional product C of the invention has general formulaAlR_(x)X_(3−x) where R is a linear or branched alkyl residue containing2 to 8 carbon atoms, X is chlorine or bromine and the value of x is 1, 2or
 3. 23. A catalytic composition according to claim 21 or claim 22characterized in that product C is isobutylaluminum sesquichloride,ethylaluminum sesquichloride, dichloroisobutylaluminum,dichloroethylaluminum, or chlorodiethylaluminum.
 24. A catalyticcomposition according to any one of claims 1 to 23 characterized in thatproduct C is used in a mole ratio of at most 1:100 with product B.
 25. Aprocess for dimerizing, co-dimerizing or oligomerizing at least oneolefin characterized in that said olefin is brought into contact with acatalytic composition according to any one of claims 1 to
 24. 26. Aprocess according to claim 25 characterized in that the dimerization,co-dimerization or oligomerization reaction is carried out in a closedsystem, in a semi-open system or in a continuous system, with one ormore reaction stages, with agitation and at a temperature of −40° C. to+70° C.
 27. A process according to claim 26 or claim 27 characterized inthat the olefins are ethylene, propylene, n-butenes and n-pentenes, usedalone or as a mixture, pure or diluted by an alkane.
 28. A processaccording to claim 25 or claim 26 characterized in that the olefins arecontained in cuts from oil refining processes.